Physicochemical characterization of rice straw before and after alkali-assist photocatalytic pretreatment: a comparative analysis.

The potential of alkali-assist photocatalytic (AAP) pretreatment to overcome the recalcitrant nature of lignocellulose biomass, i.e. rice straw (RS), was investigated in the present study. Box-Behenken Design (BBD) using standard response surface methodology (RSM) approach was considered to obtain optimal conditions for maximum delignification. The model was designed with three variables: alkali concentration (NaOH, 0-3% w/v), photocatalyst (TiO2 NPs (titania nanoparticles), 0-1 g/L) and pretreatment time (30-240 min). The availability of cellulose was increased by 96.73%, while the concentration of lignin and hemicellulose decreased by 73.89%, and 71.79%, respectively, at a combination of 1.5% NaOH, 0.5 g/L TiO2 NPs and 135 min pretreatment time. The structural and morphological alterations in the RS were assessed via Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) both before and after AAP pretreatment. The FTIR measurement indicated that the original RS included a significant quantity of lignin, which was eliminated after the pretreatment procedure. The XRD pattern demonstrates that cellulose crystallinity is significantly affected by the pretreatment. The SEM analysis revealed structural distortion and surface porosity from the pretreatment procedure.

Biogenic engineered zinc oxide nanoparticle for sulfur black dye removal from contaminated wastewater: comparative optimization, simulation modeling, and isotherms.

This research work aimed to isolate and culture the bacterium Bacillus paramycoides for biogenic fabrication of zinc oxide nanoparticles, specifically ZnO and ZnO-ME nanoparticles (nanoparticles fabricated from bacterial extracts only - ZnO, and from bacterial cell mass including extract - ZnO-ME). SEM investigation revealed the spherical-shaped NPs with 22.33 and 39 nm in size for ZnO and ZnO-ME, respectively. The Brunauer, Emmett, and Teller (BET) studies revealed mesoporous structure with pore diameters of 13.839 and 13.88 nm and surface area of 7.617 and 33.635 m2/gm for ZnO and ZnO-ME, respectively. Various parameters for the adsorption of sulfur black dye onto both ZnO and ZnO-ME were screened and optimized using Plackett-Burman Design (PBD), Full Factorial Design (FFD) and Central Composite Design (CCD). The results of the optimization modeling study revealed that FFD yielded the most predictable and best-fitting results among all the models studied, with R2 values of 0.998 for ZnO and 0.993 for ZnO-ME. Notably, ZnO-ME exhibited a greater dye removal efficiency 80% than ZnO i.e., 71%, it may be due to the presence of amorphous carbon on the surface of ZnO-ME. Among the various isothermal models, the Freundlich model displayed the strongest correlation with the dye removal data, confirming the multilayer adsorption of dye on both nanoparticles and supporting physisorption. Therefore, ZnO and ZnO-ME nanoparticles have been proven as potential tools for mitigating environmental impacts associated with dye-containing wastewater.

Ni0.5Co0.5S nano-chains: a high-performing intercalating pseudocapacitive electrode in asymmetric supercapacitor (ASC) mode for the development of large-scale energy storage devices.

Grid-scale energy storage solutions are necessary for using renewable energy sources efficiently. A supercapattery (supercapacitor + battery) has recently been introduced as a new variety of hybrid devices that engage both capacitive and faradaic charge storage processes. Nano-chain architectures of Ni0.5Co0.5S electrode materials consisting of interconnected nano-spheres are rationally constructed by tailoring the surface structure. Nano-chains of the bimetallic sulfide Ni0.5Co0.5S are presented to have a superior charge storage capacity. The Ni0.5Co0.5S nano-chain electrode presents a capacitance of 2001.6 F g-1 at 1 mV s-1, with a specific capacity of 267 mA h g-1 (1920 F g-1) at 1 A g-1 in 4 M KOH aqueous electrolyte through the galvanostatic charge-discharge (GCD) method. The reason behind the high charge storage capacity of the materials is the predominant redox-mediated diffusion-controlled pseudocapacitive mechanism coupled with surface capacitance (electrosorption), as the surface (outer) and intercalative (inner) charges stored by the Ni0.5Co0.5S electrodes are close to 46.0% and 54.0%, respectively. Additionally, a Ni0.5Co0.5S//AC two electrode full cell operating in asymmetric supercapacitor cell (ASCs) mode in 4 M KOH electrolyte exhibits an impressive energy density equivalent to 257 W h kg-1 and a power density of 0.73 kW kg-1 at a current rate of 1 A g-1.

Sequestration of Ni (II), Pb (II), and Zn (II) utilizing biogenic synthesized Fe3O4/CLPC NCs and modified Fe3O4/CLPC@CS NCs: Process optimization, simulation modeling, and feasibility study.

The present study reports low-cost novel biogenic magnetite Citrus limetta peels carbon (Fe3O4/CLPC) nanocomposites and modified Fe3O4/CLPC@CS nanocomposites cross-linked with glutaraldehyde and subsequently employed in batch mode sequestration of heavy metals ions. Diverse techniques fully characterized them, and the influence of operating variables on adsorption reactions from aqueous solutions was investigated. The Brunauer, Emmett, and Teller (BET) surface areas of synthesized Fe3O4/CLPC and Fe3O4/CLPC@CS NCs were 53.91 and 32.16 m2/g, while the mesoporous diameters were 7.69 and 7.57 nm, respectively. The Langmuir isotherm and Pseudo second order kinetic were well-fitting and capable of explaining the adsorption reaction. The Langmuir-based monolayer adsorption (qmax) for Fe3O4/CLPC@CS NCs was 82.65, 95.24, and 64.10 mg/g, higher than Fe3O4/CLPC NCs, which were 70.92, 84.75, and 59.17 mg/g for Ni (II), Pb (II), and Zn (II), respectively. Each metal's pseudo second order correlation coefficient (R2 ≥ 0.99) reveals that nanocomposites surface binding functional groups controlled the adsorption rate via chemisorption. Further, thermodynamic results confirm that each studied metal ions' adsorption was spontaneous, endothermic, and characterized by an increase in randomness. In addition to magnetic separability, three ad-desorption cycles yielded exceptional adsorption efficacy and > 93% regenerability. The present study also reveals the effective utilization of Fe3O4/CLPC and Fe3O4/CLPC@CS NCs as cost-effective magnetic separable green adsorbents for heavy metals sequestration from electroplating wastewater.

Nanocrystalline ß-NiS: a redox-mediated electrode in aqueous electrolyte for pseudocapacitor/supercapacitor applications.

Currently, enhancing the performance of electrochemical supercapacitors is the subject of intense research to fulfill the ever-increasing demand for grid-scale energy storage and delivery solution, thereby utilizing the full potential of renewable energy resources and decreasing our dependence on fossil fuels. Metal sulfides, such as cobalt sulfide (CoS), nickel sulfide (NiS), molybdenum sulfide (MoS), copper sulfide (CuS), and others, have recently emerged as a promising class of active electrode materials, alongside other supercapacitor electrode materials, due to their relatively high specific capacitance values and exceptional reversible redox reaction activities. The synthesis, characterizations, and electrochemical performances of single-phase nanocrystalline ß-NiS are presented here and the electrode based on this material shows a specific capacitance of 1578 F g-1 at 1 A g-1 from the galvanostatic discharge profile, whereas a capacitance of 1611 F g-1 at 1 mV s-1 was obtained through the CV curve in 2 M KOH aqueous electrolyte. Additionally, the electrode also performs well in neutral 0.5 M Na2SO4 electrolytes resulting in specific capacitance equivalent to 403 F g-1 at 1 mV s-1 scan rate. The high charge storage capacity of the material is due to the superior intercalative (inner) charge storage coupled with the surface (outer) charges stored by the ß-NiS electrode and was found to be 72% and 28%, respectively, in aqueous 2 M KOH electrolyte. This intercalative charge storage mechanism is also responsible for its excellent cycling stability. Additionally, we assembled aqueous asymmetric supercapacitors (ASCs) with activated carbon (AC) as the negative electrode and the ß-NiS electrode as the positive electrode. The combination of the ß-NiS electrode and AC with excellent cycling stability resulted in the highest specific energy equivalent to ∼163 W h kg-1 and a specific power of ∼507 W kg-1 at 1 A g-1 current rate.

Effect of strontium doping on the electrochemical pseudocapacitance of Y1-xSrxMnO3-δ perovskites.

Grid-scale bulk energy storage solutions are needed to utilize the full potential of renewable energy technologies. Pseudocapacitive electrochemical energy storage can play a vital role in developing efficient energy storage solutions. The use of perovskites as anion intercalation-type pseudocapacitor electrodes has received significant attention in recent years. In this study, Sr-doped YMnO3i.e. Y1-xSrxMnO3-δ perovskite was prepared by the solid-state ceramic route and studied for electrochemical pseudocapacitance in aqueous KOH electrolyte. Microstructures, morphologies, and electrochemical properties of these materials were investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance method. The formation of the mostly cubic phase, with 50% strontium doped YMnO3 (YSMO-50) provides an equivalent three-dimensional network and superior conductivity due to Mn3+-O2--Mn4+ hopping conduction. YSMO-50 exhibited low intrinsic resistance, 1.45 Ω cm-2, and the highest specific capacity, 259.83 F g-1 at a current density of 1 A g-1 in 2 M KOH aqueous electrolyte. Redox-mediated interconversion of oxide to hydroxide (M2+O2- + H2O + e- ↔ M+OH- + OH-) in aqueous media is shown to be the reason behind the high capacitance of YSMO-50. The excellent electrochemical performance of YSMOs was attributed to the reversible interconversion of oxide-ion into hydroxide ion coupled with surface redox reaction of Mn2+/Mn3+ and Mn3+/Mn4+ occurring during the charge-discharge process. The maximum energy density of 65.13 W h kg-1 was achieved at a power density of 0.45 kW kg-1 for an asymmetric mode, in which YSMO serves as a negative electrode and Activated carbon (AC) as a positive electrode in the PVA-KOH gel electrolyte. Our study reveals that the doping of low valence atom (Sr) at the A-site in perovskite manganites (YMnO3) may be an effective tool to enhance the pseudocapacitive performance of perovskite-based electrodes.

Perovskite La1-xKxCoO3-δ (0 ≤ x ≤ 0.5): a novel bifunctional OER/ORR electrocatalyst and supercapacitive charge storage electrode in a neutral Na2SO4 electrolyte.

The as-prepared La1-xKxCoO3-δ (0 ≤ x ≤ 0.5) showed superior pseudocapacitive charge storage capacity in a neutral 0.5 M Na2SO4 electrolyte and superior electrocatalytic activities for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in a 1 M KOH electrolyte. 30% K doped p-type La0.7K0.3CoO3-δ presents superior OER activity with an overpotential of ∼335 mV at 10 mA cm-2 current rate in a 1 M KOH electrolyte. Additionally, La1-xKxCoO3-δ (0 ≤ x ≤ 0.5) presents an excellent charge-storage capacitance in a neutral 0.5 M Na2SO4 electrolyte resulting in a gravimetric capacitance of the La0.5K0.5CoO3-δ electrode equivalent to 378 F g-1, 282 F g-1, 221 F g-1, 163 F g-1, and 74 F g-1 at a current density of 1 A g-1, 2 A g-1, 3 A g-1, 5 A g-1, and 10 A g-1, respectively. After 2500 continuous cycles of charge/discharge, the La0.5K0.5CoO3-δ//AC cell exhibits higher stability, capacitive retention (94%) and coulombic efficiency (97%). The gravimetric charge storage capacity of ASCs (La0.5K0.5CoO3-δ//AC) in the full cell mode showed capacitance equivalent to 308 F g-1, 287 F g-1, 238 F g-1, 209 F g-1 and 162 F g-1 at current densities of 1 A g-1, 2 A g-1, 3 A g-1, 5 A g-1 and 10 A g-1 in a neutral 0.5 M Na2SO4 electrolyte respectively. Maximum specific power equivalent to ∼6884 W kg-1 was observed at a current density of 10 A g-1 when the specific energy reached ∼57 W h kg-1 for the full cell. The double exchange mechanism coupled with stoichiometric oxygen defects present in the perovskite lattice seems to be operative behind the enhanced electrocatalytic OER properties, and additionally, it improves the charge storage kinetics of the La1-xKxCoO3-δ (0 ≤ x ≤ 0.5) electrode in a neutral Na2SO4 electrolyte for supercapacitor application. This work presents a rational strategy for introducing facile oxygen ion defects into perovskite structured La1-xKxCoO3-δ (0 ≤ x ≤ 0.5) to develop multifunctional electrode materials for a supercapacitor and energy conversion (OER/ORR) electrode of metal-air batteries.

Photocatalytic dye-degradation activity of nano-crystalline Ti1-x M x O2-δ (M =Ag, Pd, Fe, Ni and x = 0, 0.01) for water pollution abatement.

Nanocrystalline metal-ion (M = Fe, Ni, Ag, and Pd) doped and undoped anatase-TiO2 powders were prepared using a solution combustion method. The photocatalytic degradation of different dyes such as methylene blue (MB), rhodamine B (RB), rhodamine B base (RBB), and thionine acetate (TA) was investigated under UV exposure. The degradation rate of the dyes were found to be better in the case of Ag+ and Pd2+ doped TiO2, whereas Fe3+ and Ni2+ doped TiO2 showed lower photocatalytic activity compared to undoped TiO2 nanoparticles. Combustion synthesized catalysts exhibited much better activity compared to the commercial Degussa P25 (75% anatase + 25% rutile) TiO2 photocatalyst. The intermediate states created in the band gap of the TiO2 photocatalyst due to doping of first row transition metal ions (such as Fe3+ and Ni2+) into the TiO2 lattice act as recombination centres and the electrons present in the d-orbital quench the photogenerated holes by indirect recombination, hence increasing e--h+ recombination rates. As a result, a decrease in the photocatalytic activity of TiO2 doped with first row transition metal ions is observed. However, in the case of noble metal ions (such as Ag+ and Pd2+) in TiO2, photoreduction of Ag+ and Pd2+ ions occurs upon UV irradiation, hence the noble metal-ions act as electron scavengers. Consequently, the lifetime of the holes (h+) increases and hence higher photocatalytic oxidation activity of the dyes is observed. A novel strategy of electron scavenging is envisaged here to develop Ag+ and Pd2+ doped TiO2 to increase the photocatalytic oxidation of organic dyes for the development of better water pollution abatement catalysts. Redox-pair stabilization in the TiO2 lattice similar to photo-chromic glasses play a defining role in enhancing the photocatalytic activity of the catalyst and is a key finding for the development of superior photocatalysts. With the help of UV-vis and fluorescence spectroscopy, the mechanisms of the superior oxidation activity of Pd2+ and Ag+ doped TiO2 nanoparticles are explained.

SrFeO3-δ: a novel Fe4+ ↔ Fe2+ redox mediated pseudocapacitive electrode in aqueous electrolyte.

Pseudocapacitors offer both high energy and high power, making them suitable for grid-scale electrochemical energy storage to harness renewable energy produced from sun, wind, and tides. To overcome performance degradation in terms of cycling fading and lower specific capacitance values at high charge/discharge rates of electrochemical pseudocapacitors based on transition-metal oxides, perovskite-structured SrFeO3-δ was envisaged as a negative electrode that harnesses the Fe4+/3+ and Fe3+/2+ redox couple to deliver superior performance. SrFeO3-δ offers high specific capacitances of ca. 733 F g-1 at a scan rate of 1 mV s-1 and ca. 743 F g-1 at a current density of 1 A g-1 and demonstrates excellent cyclic stability over 2500 repeated cycles with capacitance retention of >92%, achieving 94% coulombic efficiency. The good cycling stability is attributed to the inherent metallic electrical conductivity of SrFeO3-δ and the fortuitous tendency of the robust cation framework structure to accommodate flexible oxygen content. The surface capacitive and diffusion-controlled contributions for capacitance are about ∼30% and ∼70%, respectively, at peak current and a scan rate equivalent to 1 mV s-1. The higher capacitance and stable performance make SrFeO3-δ an economical and abundant pseudocapacitive electrode.

La1-x K x FeO3-δ: An Anion Intercalative Pseudocapacitive Electrode for Supercapacitor Application.

The green energy alternative to a fossil fuel-based economy can be provided only by coupling renewable energy solution solutions such as solar or wind energy plants with large-scale electrochemical energy storage devices. Enabling high-energy storage coupled with high-power delivery can be envisaged though high-capacitive pseudocapacitor electrodes. A pseudocapacitor electrode with multiple oxidation state accessibility can enable more than 1e - charge/transfer per molecule to facilitate superior energy storage. K-doped LaFeO3 (La1-x K x FeO3-δ) is presented here as an electrode having a high pseudocapacitance storage, equivalent to 1.32e - charge/transfer per molecule, resulting in a capacity equivalent of 662 F/g at 1 mV/s scan rate by introduction of a layered potential over the Fe-ion octahedral to utilize higher redox state energies (Fe4+→ Fe2+). La/K ordering in orthorhombic perovskite (La1-x K x FeO3-δ) made the Fe4+ oxidation state accessible, and a systematic shift in the redox energies of Fe4+/3+ and Fe3+/2+ redox couples was observed with K+ ion doping in the A site of the LaFeO3 perovskite, which resulted in a high faradic contribution to the capacitance, coupled with anionic intercalation of H2O/OH- in the host perovskite lattice. The surface capacitive and diffusion control contributions for capacitance are about 42 and 58%, respectively, at -0.6 V, with a scan rate of 1  mV/s. A high gravimetric capacitance, equivalent to 619, 347, 188, 121, and 65 F/g, respectively, at 1, 2, 3, 5, and 10 A/g constant current, was observed for the La0.5K0.5FeO3-δ electrode. Up to 88.9% capacitive retention and 97% Coulombic efficacy were obtained for continuous 5000 cycles of charge/discharge for the La0.5K0.5FeO3-δ electrode. The gravimetric capacitance values of ASCs (activated carbon//La0.5K0.5FeO3-δ) are 348, 290, 228, and 147 F/g at current densities of 1, 2, 3, and 5 A/g, respectively. A maximum specific power of ∼3594 W/kg was obtained when the specific energy reached ∼117 Wh/kg at 5 A/g of current density.

Clear Liquids versus Polyethylene Glycol Preparation for Video Capsule Endoscopy of the Small Bowel: A Randomized Controlled Trial.

BACKGROUND: An effective bowel cleanse can improve the imaging quality of video capsule endoscopy (VCE). We aimed to further investigate the optimal small bowel cleanse method by comparing the efficacy of 4 L of clear liquids, 2 L of polyethylene glycol (PEG), and 4 L of PEG on the image quality of VCE. METHODS: A randomized controlled, non-inferiority trial was performed comparing 4 L of clear liquids (Group A), 2 L of PEG (Group B), and 4 L of PEG (Group C). The primary endpoint was image quality between the groups. The secondary endpoints included patient tolerability and side effects. RESULTS: Eighty-one patients were analyzed in group A, 84 patients were analyzed in group B, and 80 patients were analyzed in group C. Image quality scores revealed 4 L of clear liquids to be non-inferior to 2 L of PEG, and 2 L of PEG to be non-inferior to 4 L of PEG (p < 0.0167). Group A had a lower difficulty of completion rate than Group B and Group C and a lower rate of side effects when compared to Group C (p < 0.0167). CONCLUSION: Four liters of clear liquids should be considered a routine method for small bowel preparation prior to VCE.

Folate Insufficiency Due to Celiac Disease in a 49-Year-Old Woman of Southeast Asian-Indian Ethnicity.

The clinical presentation of celiac disease has evolved from chronic diarrhea and malnutrition to mild nutrient insufficiencies. Recently diagnosed adults with celiac disease should be assessed for micronutrient deficiencies because early institution of a gluten-free diet (GFD) prevents morbidity and reduces the incidence of gastrointestinal malignant neoplasms and osteoporosis. In this report, we present the case of a 49-year-old woman of Southeast Asian-Indian descent living in the United States who had folate insufficiency, as manifested by low serum and red blood cell (RBC) folate levels. Further investigation, including serologic testing and intestinal biopsy, confirmed a diagnosis of celiac disease and other nutrient deficiencies. Managing the condition of this patient with folate supplements and implementation of a recommended GFD reversed the folate insufficiency. In conclusion, when serum and/or RBC levels are low in a person of Southeast Asian-Indian descent living in a country with folate fortification of the grain supply, such as the United States, the medical team needs to look for an organic cause, as in our patient, to diagnose and manage celiac disease early and, hopefully, forestall complications.

High-rate oxygen evolution reaction on Al-doped LiNiO2.

LiNi0.8 Al0.2 O2 with a higher Ni(3+) /Li(+) ordering, synthesized by the solution-combustion method, gives oxygen-evolution-reaction (OER) activity in alkaline solution that is comparable to that of IrO2 . This confirms that the octahedral-site Ni(IV) /Ni(III) couple in an oxide is an active redox center for the OER with -redox energy pinned at the top of the O-2p bands.

Conditions for Ta(IV)-Ta(IV) bonding in trirutile Li(x)MTa2O6.

Stabilization of Ta-Ta bonding in an oxide across a shared octahedral-site edge of a Ta2 dimer is not known. Investigation of Li insertion into the trirutile structure of MTa2O6 with M = Mg, Cr, Fe, Co, and Ni indicates that Ta-Ta bonding across the shared octahedral-site edge of the dimer can be stabilized by a reversible electrochemical reduction of Ta(V) to Ta(IV) for M = Cr, Fe, Co, and Ni but not for M = Mg. Chemical reduction of MTa2O6 by n-butyl lithium only reduced NiTa2O6 to any significant extent. With M = Fe, Co, or Ni, electrochemical formation of the Ta-Ta bonds is accompanied by a partial reduction of the Fe(II), Co(II), or Ni(II) to Fe(0), Co(0), or Ni(0). For M = Cr, two Li per formula unit can be inserted reversibly with no displacement of Cr(0). For M = Mg, no Mg(II) are displaced by Li insertion, but a solid-electrolyte interphase (SEI) layer is formed on the oxide with no evidence of Ta-Ta bonding. Stabilization of Ta-Ta bonding across a shared octahedral-site edge in a dimer appears to require significant hybridization of the Ta(V) 5d(0) and M 4s(0) states.

Sn-Cu nanocomposite anodes for rechargeable sodium-ion batteries.

Sn0.9Cu0.1 nanoparticles were synthesized via a surfactant-assisted wet chemistry method, which were then investigated as an anode material for ambient temperature rechargeable sodium ion batteries. The Sn0.9Cu0.1 nanoparticle-based electrodes exhibited a stable capacity of greater than 420 mA h g(-1) at 0.2 C rate, retaining 97% of their maximum observed capacity after 100 cycles of sodium insertion/deinsertion. Their performance is considerably superior to electrodes made with either Sn nanoparticles or Sn microparticles.

Primary sclerosing cholangitis: etiopathogenesis and clinical management.

Primary sclerosing cholangitis (PSC) is a chronic inflammatory liver disease characterized by the destruction of medium to large-sized bile ducts and intense, concentric fibrosis. Complications from PSC include bacterial cholangitis, cirrhosis, and cholangiocarcinoma and a therapy that might alter the natural history of the disease remains lacking. Our understanding of the pathogenesis of PSC also remains rudimentary but several theories exist, suggesting roles for genetic susceptibility, abnormal innate immune responses lymphocyte trafficking, and toxic bile formation. Medical and surgical therapies, short of liver transplantation, have been disappointing. Currently, the management of PSC is aimed largely at the endoscopic treatment of dominant biliary strictures and complications of cholestasis until the disease has progressed to cirrhosis, at which time liver transplantation is indicated. Progress in our basic understanding of PSC is desperately needed in order to rationally design new therapeutic approaches to this disease.

Evaluation of spinal and epidural anaesthesia for day care surgery in lower limb and inguinoscrotal region.

BACKGROUND: Day care surgery is still in its infancy in India. Both regional and general anaesthesia can be used for this. Central neuraxial blocks are simple cheap and easy to perform. This study was done to evaluate usefulness of spinal and epidural anaesthesia for day care surgery. PATIENTS #ENTITYSTARTX00026; METHOD: 100 patients were randomized to either spinal (n=50) or epidural (n=50) group anaesthetized with either 0.5% hyperbaric 2ml bupivacaine or 0.5% 20ml bupivacaine respectively. In spinal group 27 gauze quincke needle and in epidural group 18 gazue tuohy needle was used. Both the groups were compared for haemodynamic stability, side effects, complications, postanaesthesia discharge score (PADS), time taken to micturate, total duration of stay in hospital and patient satisfaction score for technique. RESULTS: We observed that spinal anaesthesia had significantly early onset of anaesthesia and better muscle relaxation (p<0.05) as compared to epidural block otherwise both groups were comparable for haemodynamic stability, side effects or complications. Although more patients in spinal group (64% vs 48%) achieved PADS earlier (in 4-8 hours) but statistically it was insignificant. Time to micturition (6.02 0.55 v/s 6.03 0.47 hours) and total duration of stay (7.49 1.36 v/s 8.03 1.33 hours) were comparable in both the groups. CONCLUSION: Both spinal and epidural anaesthesia can be used for day care surgery. Spinal anaesthesia with 27 gauze quincke needle and 2ml 0.5% hyperbaric bupivacaine provides added advantage of early onset and complete relaxation.

Comparative evaluation of ketamine - propofol, fentanyl - propofol and butorphanol-propofol on haemodynamics and laryngeal mask airway insertion conditions.

BACKGROUND: Laryngeal mask airway is a non invasive supraglottic device which has led to a radical change in the management of modern general anaesthesia. Propofol as a single agent is unsatisfactory and to overcome problems associated with LMA insertions. In the present study, we evaluated the haemodynamic changes and laryngeal mask airway insertion conditions comparing ketamine and opioids as adjuncts to propofol. PATIENTS AND METHODS: 90 patients were randomly divided into 3 groups of 30 each. In Group PK-ketamine 0.5mg kg(-1), in Group PF-fentanyl 1ug kg(-1) and in Group PB - butorphanol 20ug kg(-1) was given intravenously immediately before induction with propofol 2.5 mg kg(-1). Jaw relaxation was assessed according to Young's criteria and the overall conditions according to modified Scheme of Lund and Stovener. RESULTS: The mean total dose of propofol required in Group PK was 160.37 ± 15.75mg, in Group PF 156.22 ± 17.18 mg and in Group PB 140.08 ± 18.97 mg. The incidence of absolute jaw relaxation was highest in Group PB (93.33%) patients, intermediate in Group PF (53.33%) patients and lowest in Group PK i.e. 36.66% patients. Excellent insertion conditions were observed in 12 (40%) patients in Group PK and 13 (43.33%) patients in Group PF and in 26 (86.67%) patients in Group PB. Group PK showed more rise in systolic and diastolic blood pressure and heart rate post LMA insertion as compared to Group PF and Group PB. CONCLUSION: It is concluded that addition of butorphanol to propofol for LMA insertion provided absolute jaw relaxation and excellent insertion conditions with stable haemodynamics Side effects like coughing, gagging, lacrimation and laryngospasm were lower as compared to the other two groups.

Structure of Ce(1-x)Sn(x)O(2) and its relation to oxygen storage property from first-principles analysis.

CeO(2)-SnO(2) solid solution has been reported to possess high oxygen storage/release property which possibly originates from local structural distortion. We have performed first-principles based density functional calculations of Ce(1-x)Sn(x)O(2) structure (x=0, 0.25, 0.5, 1) to understand its structural stability in fluorite in comparison to rutile structure of the other end-member SnO(2), and studied the local structural distortion induced by the dopant Sn ion. Analysis of relative energies of fluorite and rutile phases of CeO(2), SnO(2), and Ce(1-x)Sn(x)O(2) indicates that fluorite structure is the most stable for Ce(1-x)Sn(x)O(2) solid solution. An analysis of local structural distortions reflected in phonon dispersion show that SnO(2) in fluorite structure is highly unstable while CeO(2) in rutile structure is only weakly unstable. Thus, Sn in Ce(1-x)Sn(x)O(2)-fluorite structure is associated with high local structural distortion whereas Ce in Ce(1-x)Sn(x)O(2)-rutile structure, if formed, will show only marginal local distortion. Determination of M-O (M=Ce or Sn) bond lengths and analysis of Born effective charges for the optimized structure of Ce(1-x)Sn(x)O(2) show that local coordination of these cations changes from ideal eightfold coordination expected of fluorite lattice to 4+4 coordination, leading to generation of long and short Ce-O and Sn-O bonds in the doped structure. Bond valence analyses for all ions show the presence of oxygen with bond valence approximately 1.84. These weakly bonded oxygen ions are relevant for enhanced oxygen storage/release properties observed in Ce(1-x)Sn(x)O(2) solid solution.

Documenting and improving opioid treatment: the Prescription Opioid Documentation and Surveillance (PODS) System.

OBJECTIVE: To demonstrate that a computer-assisted survey instrument offers an efficient means of patient evaluation when initiating opioid therapy. Design. We report on our experience with the Prescription Opioid Documentation and Surveillance (PODS) System, a medical informatics tool that uses validated questionnaires to collect comprehensive clinical and behavioral information from patients with chronic pain. SETTING AND PATIENTS: Over a 39-month period, 1,400 patients entered data into PODS using a computer touch screen in a Veterans Administration Pain Clinic. MEASURES: Indices of pain intensity, function, mental health status, addiction history, and the potential for prescription opioid abuse were formatted for immediate inclusion into the medical record. RESULTS: The PODS system offers physicians a tool for systematic evaluation prior to prescribing opioids The system generates an opioid agreement between the patient and physician, and provides medicolegal documentation of the patient's condition. CONCLUSIONS: PODS should improve patient care, refine pain control, and reduce the incidence of opioid abuse. Research to determine how PODS affects clinical care is underway. Specially, the effectiveness and efficiency of providing care utilizing PODS will be evaluated in future studies.